--dump=D

Okay, I need to remember this once for all. I'm frequently using gcc [OPTIONS] someFile.c -E to understand some of the error messages from the compiler, but too often, I have to ask a crawling duck what preprocessor option would let me see the values of the #define statements, not just the lines of code with all substitutions applied. So it's time I post something to remember me it's -dD

...

Or maybe I could just add some line in my cpp-output-colorizer that would remind me of it ?